JPH0360672A - Storage needle - Google Patents

Abstract

PURPOSE:To prevent a storage needle during the storage in blood vessel from giving pain or damaging a blood vessel despite movement of the base of needle at an extra-vessel site by constituting the storage needle by an intra-vessel part made of a stainless steel and an extra-vessel part made of a shape memory resin having a specific mean glass transition point temp. CONSTITUTION:An intra-vessel part of needle is made of a stainless steel, for ex. SUS 304, while an extra-vessel part of needle made of a shape memory alloy whose mean glass transition point temp. ranges from 20 to 37 deg.C. The shape memory resin is a resin composite whose changing ratio of the modulus of elasticity before and after the glass transition point is two or more, the examples being of polyurethane type, polynorbornen type, and transpolyisoprene type. Its mean glass transition point temp. shall preferably be 25-35 deg.C so that the extra-vessel part does not soften before puncture and that softening after storage is less time-consuming. Use of this storage needle provides a small puncture resistance at the puncturing time in a blood vessel, etc., and does not generate twist in the external needle, which enables safe and certain puncture. Eventual movement of the base of the extra-vessel part after storage does not give pain, thus contributing to reduce pain of patients.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a tube for indwelling in the body, and more specifically, for medical purposes such as injecting a drug solution into a patient or extracorporeally circulating blood during artificial dialysis. This invention relates to an indwelling needle that is used by being placed in an indwelling needle.

The indwelling needle here refers to a hollow outer needle and an inner needle (G needle) inserted into the outer needle.After inserting this into the patient's body, the inner needle is pulled out and only the outer needle is removed. A device configured to be placed inside a blood vessel.

<Prior art> Indwelling needles used for infusions, blood transfusions, etc. are generally composed of an inner needle that is a hollow metal needle and an outer hollow needle made of flexible resin. After this is inserted into the patient's blood vessel, the inner needle is withdrawn, leaving only the outer needle indwelled in the blood vessel.

Since the outer needle of an indwelling needle is placed in the blood vessel, it is preferable that it be flexible so as not to damage the straight tube, but if the outer needle is too soft, the tip of the outer needle will curl and deform during puncture, so conventional Generally, fluororesins such as tetrafluoroethylene hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, and polypropylene are used as materials for forming the outer needle.

<io> to be solved by the invention> However, in the conventional indwelling needle described above, when the base is moved with the outer needle indwelled, the outer needle does not have sufficient flexibility, so the outer needle presses against the blood vessel wall. This poses a problem as it may cause pain to the patient and may damage the blood vessel wall.

The present invention was developed in consideration of the above-mentioned problem, and is hard when punctured into a blood vessel, so the tip does not curl up, and becomes flexible after being placed in a blood vessel, making it possible to use an external needle. To provide a new type of indwelling needle that does not cause pain or damage blood vessels even if the base of the outer needle moves inside.

<Means for Solving the Problems> In order to solve the above problems, the present invention has an inner needle made of stainless steel and a shape memory resin having an average glass transition temperature between 20°C and 37°C. It uses an indwelling needle that is separated from the outer needle.

Suitable shape memory resins include polyurethane shape memory resins, polynorbornene shape memory resins, transpolyisoprene shape memory resins, and the like.

Note that the term "shape memory resin" as used herein refers to a resin composition in which the ratio of change in elastic modulus before and after the force-lass transition point is 2 or more.

Effect> According to the above configuration, when the indwelling needle is punctured, the outer needle is hard, so the tip does not curl up, and after the indwelling needle (or more accurately, the outer needle) is placed, the outer needle is hard. Because it is soft, even if the base of the indwelling needle moves, it will not cause pain or damage the blood vessels.

<Example> Next, examples of the present invention will be described.

The indwelling needle of the present invention is an indwelling needle consisting of an inner needle of metal and an outer needle of synthetic resin, and is characterized in that the inner needle is made of shape memory resin. The inner needle is made of stainless steel, such as 5US304, and the outer needle is made of a shape memory resin whose average glass transition temperature is between 20°C and 37°C. The shape memory resin is a resin composition in which the ratio of change in elastic modulus before and after the glass transition point is 2 or more, and polyurethane-based, polynorbornene-based, and transpolyisoprene-based shape memory resins are generally used. The average glass transition temperature of the shape memory resin is preferably 25°C to 35°C so that the outer needle does not become soft before being punctured and so that it does not take time to become soft after being placed in rg1.

[Example 1] As an indwelling needle, an outer needle (inner diameter 0.8++++++, outer diameter 1.
1 m [ll] of polyurethane shape memory resin (manufactured by Mitsubishi Heavy Industries, Ltd., MM-3500: average glass transition temperature 35°C 12
Spring hardness at 5°C: 90-95.36°C spring hardness: 60-65) was prepared, and the thickness was 0.
．． When a puncture test was conducted using a polyvinyl chloride film of 411Im, the results shown in Table 1 were obtained.

The spring hardness was determined in accordance with JIS K6301 using a spring type hardness tester, Type A: Quality Rubber Hardness Meter Model 200 (trade name, manufactured by ■Kansetsu Seisakusho).

The penetration resistance was good with no significant difference from the fluororesin (95 g), and the tip did not curl or deform.

[Example 2] Made of 5US304, length 325 mm, outer diameter 0.8
A needle (puncture needle) made of the same resin as in Example 1, length 300 mm, inner diameter 0.8 barrel, outer diameter 1.1 a
An indwelling needle consisting of all outer needles (catheters) was prepared and inserted into the vein, the inner needle was withdrawn, and the outer needle was rotated and delivered to a desired position within the blood vessel. Although it required some skill, torque transmission was good, and the tube could be placed in a straight tube without using an introducer.

(Comparative Examples 1 to 2) Indwelling needles with outer needles made of ethylene-tetrafluoroethylene copolymer (manufactured by Mitsui Fluoroke Dancal, Tefzel) and polyurethane (manufactured by Kasei Upjohn, Peresene) were prepared. Then, the same piercing test as in Example 1 was conducted.The results are shown in Table 1.

The needle made of ethylene-tetrafluoroethylene copolymer had good puncture resistance, but all subjects complained of pain when moving the outer needle after placement, and the tip of the polyurethane needle rolled up during puncture. However, data could not be obtained because the tip was deformed and could not penetrate the skin.

Table 1 (hereinafter omitted) <Effects of the Invention> As is clear from the above explanation, when the indwelling needle of the present invention is used, the penetration resistance is small when the indwelling needle is inserted into a blood vessel, etc. There is no chance of damage to the outer needle of the indwelling needle, so it can be safely and reliably inserted into blood vessels, etc. 11 people are possible. Furthermore, since there is no pain even if the base of the outer needle moves after placement, the patient's pain is reduced.

Claims (1)

[Claims] 1) An inner needle made of stainless steel and an average glass transition temperature of 20
An indwelling needle consisting of an outer needle made of a shape memory resin with a temperature between 37°C and 37°C. 2) The indwelling needle according to claim 1, wherein the shape memory resin is any one selected from the group consisting of polyurethane shape memory resin, polynorbornene shape memory resin, and transpolyisoprene shape memory resin.